Studies of the electroencephalographic (EEG), electromyographic (EMG), and sleep-awake activities of acute ethanol administration are being conducted in this laboratory. These investigators have revealed that acute oral injection of ethanol produces dose-related increases in non-REM sleep and decreases in REM sleep. The objective of this research proposal is to extend our studies to the development of tolerance to and physical dependence on ethanol by studying 24-hour sleep-awake patterns (specifically the incidence and duration of REM sleep episodes) in rats. Animals will be prepared with chronic EEG and EMG electrodes and i.v. cannuale. Also, blood-ethanol concentrations will be determined by gas chromatographic assay and correlated with occurrence of REM sleep and animal behavior. The time-course and severity of withdrawal symptoms and the duration of EEG, behavioral and sleep-awake changes subsequent to withdrawal of ethanol from physically-dependent rats will be assessed. It is anticipated that by carefully controlling pertinent variables such diet, age, previous ethanol history, and withdrawal conditions, the influence of chronic ethanol administration and withdrawal on REM sleep can be clarified.